KR101339380B1 - Rubber composition for tire and tire - Google Patents

Abstract

An object of the present invention is to provide a rubber composition for a tire having improved workability and wear resistance. In order to achieve this object, the present invention provides a synthetic composition comprising: (i) Mooney viscosity (ML) 40 to 49 synthesized with a high cis polybutadiene synthesized using a cobalt catalyst; (ii) the molecular weight distribution [weight average molecular weight (Mw) / number average molecular weight (Mn)] satisfies the requirements of 3.0 to 3.9 and (iii) the rate dependency index (n value) of Mooney viscosity is 2.3 to 3.0, Rubber composed of 5 to 90 parts by weight of a high sheath polybutadiene (a) having a ratio of the cis structure in the microstructure analysis to 95% or more, and diene rubber (b) other than the above (a). It is related with the rubber composition for tires characterized by mix | blending 1-100 weight part of rubber reinforcement agents (c) with respect to 100 weight part of components (a) + (b).

Rubber composition for tires, high sheath polybutadiene, rubber reinforcing agent.

Description

Rubber composition and tires for tires {RUBBER COMPOSITION FOR TIRE AND TIRE}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a rubber composition and tire for a tire having excellent kneading processability and improved abrasion resistance. The present invention relates to a tire outer member such as a tread and a sidewall of a tire, a carcass, a belt, and a bead. It can be used for a tire inner member of the back.

Polybutadiene is a so-called microstructure, which is a binding moiety (1,4-structure) produced by polymerization at 1,4-position and a bonded moiety (1,2-structure) produced by polymerization at 1,2-position ) Coexist in the molecular chain. 1,4-structure can be further divided into two types, cis structure and trans structure. On the other hand, the 1,2-structure has a structure in which a vinyl group is a side chain.

It is known that the polybutadiene from which the said microstructure differs is manufactured by a polymerization catalyst and superposition | polymerization conditions, and it is used for various uses by those characteristics.

In order to improve abrasion resistance and heat generation resistance of a tire, incorporation of polybutadiene rubber (BR) into natural rubber and the like has been widely performed, and various proposals have been made for BR. For example, Japanese Unexamined Patent Publication No. 7-118443 (Patent Document 1) discloses a BR having a weight average molecular weight of 500,000 to 750,000, a molecular weight distribution of 1.5 to 3.0, and an intrinsic viscosity of 90 or more. Japanese Patent Laid-Open No. 2001-247721 (Patent Document 2) discloses a BR having a cis content of 95% or more and a molecular weight distribution of 3.5 to 6.0, and also Japanese Laid-Open Patent Publication No. 2004-339467 (Patent Document 3). A BR of 95% or more, ML viscosity (Mooney viscocity: pattern viscosity) of 30 to 42, a ratio of 5% toluene solution viscosity and ML of 1.8 to 5.0, and a molecular weight distribution of 2.5 to 3.8 is disclosed.

In addition, Japanese Patent Application Laid-Open No. 2004-339466 (Patent Document 4) discloses a sheath content of 95% or more, an ML viscosity of 50 to 70, and 5% toluene for the purpose of improving tire wear resistance and flexural cracking characteristics. BRs having a ratio of solution viscosity and ML of 1.8 to 5.0 and a molecular weight distribution of 1.8 to 3.8 are disclosed.

BR used for tires increases the wear resistance when the molecular weight is increased, but the workability is lowered. When the molecular weight distribution is widened, the workability is improved, but the wear resistance and the resilience are deteriorated. Thus, improvement in workability and wear resistance is required.

Patent Document 1: Japanese Patent Application Laid-Open No. 7-118443

Patent Document 2: Japanese Unexamined Patent Publication No. 2001-247721

Patent Document 3: Japanese Unexamined Patent Publication No. 2004-339467

Patent Document 4: Japanese Unexamined Patent Publication No. 2004-339466.

DISCLOSURE OF INVENTION

Challenges to be solved by the invention

Here, an object of the present invention is to provide a rubber composition for a tire and a tire having improved workability and wear resistance.

Means for solving the problem

In order to achieve the above object, the present invention provides a high cis polybutadiene synthesized using a cobalt-based catalyst (i) Mooney viscosity (ML): 40 to 49; (ii) Molecular weight distribution [weight average molecular weight (Mw) / number average molecular weight (Mn)]: 3.0 to 3.9 and (iii) Mooney viscosity rate dependency index (n value): 2.3 to 3.0 (n value is the following formula 1 5 to 90 parts by weight of a high cis polybutadiene (a) having a requirement of 95% or more and a diene system other than the above (a). Rubber (b) It relates to the rubber composition for tires characterized by mix | blending 1-100 weight part of rubber reinforcement agents (c) with respect to 100 weight part of rubber components (a) + (b) which consist of 90-5 weight part of rubbers.

[Equation 1]

log (ML) = log (K) + n ^-1 × log (RS)

(Where RS is the number of revolutions per minute of the rotor and K is an arbitrary number)

The rubber composition for tires described above, wherein the ratio (Tcp / ML) of the 5 wt% toluene solution viscosity (Tcp) and the Mooney viscosity (ML) of the high sheath polybutadiene of (a) is 2.5 to 3.5. will be.

The above-mentioned rubber composition for tires, wherein Mw of the high sheath polybutadiene of (a) is 500,000 to 700,000, and Mn is 120,000 to 250,000.

The rubber reinforcing agent of the above (c) relates to the rubber composition for tires described above, wherein the rubber reinforcing agent is carbon black and / or silica.

The diene rubber of (b) relates to the rubber composition for tires described above, wherein the rubber is natural rubber and / or isoprene rubber.

A tire comprising the rubber composition for a tire as a rubber base.

Effects of the Invention

The polybutadiene composition in the present invention is composed of a rubber component and a rubber reinforcing agent containing a specific high cis polybutadiene, and the rubber component and the reinforcing agent are mixed well from the beginning at the time of kneading blending, so that the processability is excellent. At the same time, it is possible to provide a polybutadiene composition and a tire suitable for a tire having improved wear resistance.

The polybutadiene of the present invention has the following characteristics.

Mooney viscosity is preferably 40 to 49, more preferably 40 to 47. When a Mooney viscosity is larger than the said range, kneading workability will fall, and if it is smaller than the said range, abrasion resistance may fall and it is unpreferable.

Molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) is 3.0-3.9, More preferably, it is 3.0-3.6. When molecular weight distribution is larger than the said range, abrasion resistance falls and when it is smaller than the said range, roll workability may worsen and it is unpreferable.

The weight average molecular weight (Mw) is preferably 500,000 to 700,000, more preferably 550,000 to 650,000. When larger than the said range, roll workability will fall, and when smaller than the said range, abrasion resistance may fall and it is unpreferable.

The number average molecular weight (Mn) is preferably 120,000 to 250,000, more preferably 150,000 to 220,000. When larger than the said range, roll workability will fall, and when smaller than the said range, abrasion resistance may fall and it is unpreferable.

The rate dependency index (n value) of the Mooney viscosity is 2.3 to 3.0, preferably 2.4 to 2.9, more preferably 2.4 to 2.8. If the value of n is less than 2.3, the mixing properties of the filler deteriorate. If the value of n is larger than 3.0, the resilience decreases, which is not preferable.

The n value is determined by the degree of branching and molecular weight distribution of the polybutadiene, and has no correlation with the Mooney viscosity. The larger the branching degree and molecular weight distribution of the polybutadiene, the larger the value of n. On the contrary, the smaller the branching degree or molecular weight distribution, the smaller the value of n.

Moreover, since operation of the range of n value needs to optimize molecular weight distribution also, it can carry out in two steps as follows, for example. First, in the polymerization step of butadiene, some kinds of polybutadienes having small n values and different molecular weights are polymerized. Next, the n-value is adjusted to an optimum range by mix | blending several types of said polybutadienes from which molecular weight differs, and broadening molecular weight distribution. The n value in the polymerization step can be adjusted by the mixing molar ratio of the organoaluminum compound as the promoter and water. That is, the mixing molar ratio becomes small by increasing the addition amount of water with respect to a predetermined amount of organoaluminum compound, and n value tends to become small as mixing molar ratio becomes small. The mixing molar ratio of the organoaluminum compound which is a promoter in the polymerization step and water is preferably 2.0 or less, particularly preferably 1.0 to 1.5. If the mixing molar ratio is 2.0 or more, the n-value is too large, and if it is less than 1.0, the polymerization activity may be remarkably lowered, which is not preferable.

The ratio (Tcp / ML) of the 5% toluene solution viscosity (Tcp) and the Mooney viscosity (ML) is preferably 2.5 to 3.5, more preferably 2.5 to 3.0.

If the Tcp / ML ratio is larger than the above range, the cold flow property of the raw material rubber becomes large. If the Tcp / ML ratio is less than the above range, the wear resistance is lowered, which is not preferable.

It is preferable that cis-1,4 content is 95% or more, 97% or more is more preferable, and 98% or more is especially preferable. If cis-1,4 content is below the above, since abrasion resistance falls, it is unpreferable.

The polybutadiene may be prepared by a cobalt catalyst. As a cobalt type catalyst composition, the catalyst system which consists of (A) cobalt compound, (B) halogen containing organoaluminum compound, and (C) water is mentioned.

As the cobalt compound, a salt or a complex of cobalt can be preferably used. Particularly preferred are cobalt salts such as cobalt chloride, cobalt fluoride, cobalt nitrate, cobalt octylic acid (ethylhexanoic acid), cobalt naphthenic acid, cobalt acetate, and cobalt malonic acid; Cobalt bisacetyl acetonate, trisacetyl acetonate; Acetoacetic acid ethyl ester cobalt; Organic base complexes such as pyridine complex or picoline complex of cobalt salt; Or an ethyl alcohol complex.

Examples of the halogen-containing organoaluminum include trialkylaluminum, dialkylaluminum chloride, dialkylaluminum bromide, alkylaluminum sesquichloride, alkylaluminum sesquibromide, alkylaluminum dichloride and the like.

Specific examples of the compound include trialkylaluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexyl aluminum, trioctyl aluminum and tridecyl aluminum.

In addition, organic aluminum halogen compounds such as dialkylaluminum chloride such as dimethylaluminum chloride and diethylaluminum chloride, sesquiethylaluminum chloride and ethylaluminum dichloride, diethylaluminum hydride, diisobutylaluminum hydride and sesqui Hydrogenated organoaluminum compounds such as ethylaluminum hydride are also included. These organoaluminum compounds can be used together 2 or more types.

The molar ratio (B) / (A) of the component (A) and the component (B) is preferably 0.1 to 5000, more preferably 1 to 2000.

The molar ratio (B) / (C) between the component (B) and the component (C) is preferably 0.7 to 5, more preferably 0.8 to 4, and particularly preferably 1 to 3.

In addition to butadiene monomers, isoprene, 1,3-pentadiene, 2-ethyl-1,3-butadiene, 2,3-dimethylbutadiene, 2-methylpentadiene, 4-methylpenta Conjugated dienes such as dienes, 2,4-hexadiene, ethylene, propylene, butene-1, butene-2, isobutene, pentene-1, 4-methylpentene-1, hexene-1, octene-1 and the like Cyclic monoolefins such as acyclic monoolefin, cyclopentene, cyclohexene, norbornene, and / or aromatic vinyl compounds such as styrene and α-methylstyrene, dicyclopentadiene, and 5-ethylidene-2- You may contain a small amount of nonconjugated diolefins, such as norbornene and a 1, 5- hexadiene.

There is no restriction | limiting in particular in polymerization method, The bulk polymerization (bulk polymerization), solution polymerization, etc. which use conjugated diene compound monomer itself, such as 1, 3- butadiene, as a polymerization solvent can be applied. As a solvent in solution polymerization, Aromatic hydrocarbons, such as toluene, benzene, and xylene; alicyclic hydrocarbons such as aliphatic hydrocarbons such as n-hexane, butane, heptane and pentane, cyclopentane and cyclohexane; Olefin hydrocarbons such as the above olefin compound, cis-2-butene, and trans-2-butene; Hydrocarbon solvents such as mineral spirit, solvent naphtha and kerosene; Halogenated hydrocarbon solvents, such as methylene chloride, etc. are mentioned.

Among these, toluene, cyclohexane or a mixture of cis-2-butene and trans-2-butene can be suitably used.

The polymerization temperature is preferably in the range of -30 to 150 ° C, particularly preferably in the range of 30 to 100 ° C. The polymerization time is preferably in the range of 1 minute to 12 hours, particularly preferably 5 minutes to 5 hours.

After the polymerization for a predetermined time, the interior of the polymerization tank is subjected to post-treatment such as pressure release, washing, and drying step as necessary.

As diene rubber (b) other than said (a) of this invention, a high cis polybutadiene rubber, a low cis polybutadiene rubber (BR), emulsion polymerization, or solution polymerization styrene butadiene Rubber (SBR), natural rubber, polyisoprene rubber, ethylene propylene diene rubber (EPDM), nitrile rubber (NBR), butyl rubber (IIR), chloroprene rubber (CR) and the like.

In addition, derivatives of these rubbers, for example, polybutadiene rubber modified with a tin compound, epoxy-modified, silane-modified, maleic acid-modified rubber and the like can also be used, and these rubbers may be used alone or in combination of two or more thereof. It is okay.

Examples of the rubber reinforcing agent of the component (c) of the present invention include inorganic reinforcing agents such as various carbon blacks, white carbons, activated calcium carbonates, and ultrafine magnesium silicate, polyethylene resins, polypropylene resins, high styrene resins, phenol resins, lignin, and modified compounds. Organic reinforcing agents such as melamine resin, coumarone indene resin and petroleum resin; Especially preferably, it is carbon black whose particle diameter is 90 nm or less and dibutyl phthalate (DBP) oil absorption amount is 70 ml / 100g or more, For example, FEF, FF, GPF, SAF, ISAF, SRF, HAF etc. are mentioned. have. The mixing ratio of the rubber composition of the present invention is a rubber component composed of 5 to 90% by weight of a specific high cis polybutadiene (a) and 90 to 5% by weight of diene rubber (b) other than the above (a) ( 100 parts by weight of a) + (b) and 1 to 100 parts by weight of the rubber reinforcing agent (c).

More preferably, rubber component (a) + (b) which consists of 10 to 70 weight% of specific high cis polybutadiene (a), and 90 to 30 weight% of diene rubbers (b) other than said (a). ) 100 parts by weight and the rubber reinforcing agent (c) 10 to 70 parts by weight.

The rubber composition of the present invention can be obtained by kneading each component using a banbury, an open roll, a kneader, a twin-screw kneader, or the like.

The rubber composition of the present invention may be kneaded with a compounding agent usually used in the rubber industry, such as a vulcanizing agent, a vulcanizing aid, an anti-aging agent, a filler, process oil, zincation, stearic acid, and the like, as necessary.

As the vulcanizing agent, known vulcanizing agents such as sulfur, organic peroxides, resin vulcanizing agents, metal oxides such as magnesium oxide and the like can be used.

As the vulcanization aid, known vulcanization aids such as aldehydes, ammonias, amines, guanidines, thioureas, thiazoles, thiurams, dithiocarbamates, xanthates and the like can be used.

Examples of the anti-aging agent include amine-ketone series, imidazole series, amine series, phenol series, sulfur series and phosphorus series.

Examples of the filler include organic fillers such as inorganic fillers such as calcium carbonate, basic magnesium carbonate, clay, lead monoxide and diatomaceous earth, regenerated rubber and powdered rubber.

The process oil may be any of aromatic, naphthenic and paraffinic.

Hereinafter, the Example based on this invention is described concretely.

The microstructure was performed by infrared absorption spectral analysis. The microstructure was calculated from the absorption intensity ratios of cis 740 cm ^-1 , trans 967 cm ^-1 and vinyl 910 cm ^-1 .

The molecular weight (Mw, Mn) was measured by GPC method: HLC-8220 (manufactured by Tosoh Corporation) and calculated by standard polystyrene conversion.

Toluene solution viscosity (Tcp) is obtained by dissolving 2.28 g of a polymer in 50 ml of toluene, and then using a standard solution for calibration of viscometer (JIS Z8809) as a standard solution, and using a Canon-Fenske viscometer No. Using 400, it measured at 25 degreeC.

The Mooney viscosity (ML _{1 +4} , 100 degreeC) of a raw material rubber and a compound was measured based on JIS-K6300.

n value changes the rotational speed (1 / min) of a rotor based on JIS 6300, and measures the Mooney viscosity, and the slope of the straight line obtained by Formula 2 from Mooney viscosity (ML) and rotor rotation speed (RS) Is the inverse of. Here, log (K) is an arbitrary number meaning the intercept of the straight line.

[Equation 2]

log (ML) = log (K) + n ^-1 × log (RS)

In addition, Equation 2 can be obtained based on the theoretical formula (Equation 3) of the n-th law for non-Newtonian flow.

[Equation 3]

γ = kτ ⁿ

However, γ: velocity gradient, τ: shear stress, k ^-1 = η: viscosity coefficient

Kneading processability uses a Laboplast mill (manufactured by Toyo Seiki Seisakusho), mixes the rubber raw material for 1 minute at a starting temperature of 90 ° C. and a predetermined filling rate, and then contains carbon black or the like. After the filler was charged, the time from the increase of the torque was measured, and the comparative example 1 was represented by 100 as an index (the smaller the index, the better).

The blended ML was represented by the index as Comparative Example 1 as 100 according to the measurement method specified in JIS-K6300 (the smaller the index, the better).

Hardness was measured by the durometer type (type A) according to the measuring method prescribed | regulated to JIS-K6253, and the comparative example 1 was made into 100 and represented by the index (the larger the index, the higher the hardness).

300% tensile stress was measured by the tensile velocity 500mm / min by the No. 3 dumbbell according to the measuring method prescribed | regulated to JIS-K6251, and the comparative example 1 was represented by 100 as an index (the higher the index, the more favorable). ).

Tensile strength was measured at the tensile speed of 500 mm / min with the No. 3 dumbbell according to the measuring method prescribed | regulated to JIS-K6251, and the comparative example 1 was represented by 100 as the index (the higher the index, the more favorable).

Repulsive elasticity was measured by tripping according to the measurement method specified in JIS-K6251, and the comparative example 1 was represented by 100 as an index (the higher the index, the better).

Lambbourn abrasion was measured at a slip rate of 20% according to the measurement method specified in JIS-K6264, and the comparative example 1 was represented as 100 using an index (the larger the index, the better).

( Example  1 to 3, Comparative Example  1 to 5)

First, cispolybutadiene (polymerization examples 1 to 5) used in Examples 1 to 3 and Comparative Examples of the rubber composition for tires according to the present invention were prepared. 1.0 liter (butadiene; 31.5 weight%, 2-butenes; 28.8 weight%, cyclohexane; 39.7 weight%) of polymerization solution was put into the stainless steel reaction tank with the internal volume of 1.5 liters substituted with nitrogen gas, and water 2.2 mmo1, diethylaluminum chloride 2.9 mmol (organic aluminum / water mixing molar ratio = 1.3), cyclooctadiene (COD) variable amount, cobalt octoate 0.005 mmol were added, and it stirred at 60 degreeC for 20 minutes, and the 1, 4- sheath The polymerization was carried out. The ethanol solution which is an anti-aging agent was added to this, and superposition | polymerization was stopped. Thereafter, unreacted butadiene and 2-butenes were evaporated to remove cispolybutadiene. Table 1 shows cispolybutadienes according to the polymerization examples 1 to 5 obtained by changing the amount of cyclooctadiene.

COD (mmol) Intrinsic viscosity [η] Mooney viscosity 5% Toluene Solution Viscosity n value Polymerization Example 1 0.8 3.5 - - - Polymerization Example 2 3.2 2.6 60 156 2.0 Polymerization Example 3 4.0 2.5 52 130 2.0 Polymerization Example 4 16.0 1.7 27 68 1.9 Polymerization Example 5 64.0 0.8 - - -

Next, the cispolybutadiene according to the polymerization examples 1 to 5 was dissolved in cyclohexane at the ratio shown in Table 2 and blended, followed by evaporating off the cyclohexane to mix the mixed cispolybutadiene according to the prototypes 1 to 4. Got.

Prototype 1 Prototype 2 Prototype 3 Prototype 4 Polymerization Example 1 27 23 18 25 Polymerization Example 2 - - - 50 Polymerization Example 3 50 60 70 - Polymerization Example 4 - - - 25 Polymerization Example 5 23 17 12 -

Next, mixed cis polybutadiene (BR) according to Prototypes 1 to 3 was used as Examples 1 to 4, and commercially available cis polybutadiene (BR150L, BR700, BR150B, and BR230, all manufactured by Ube Kosan Co., Ltd.) ) And the mixed cispolybutadiene according to Prototype 4 were used as Comparative Examples 1 to 5, and physical properties of these raw rubbers (BR) were measured. In addition, based on the formulation shown in Table 3, using a LaboPlast mill BR-250 (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the temperature was set at 90 ° C and a rotational speed of 68 rpm, and the raw material rubber (BR) and NR were used. After mixing for 1 minute, the compounding agent except the vulcanizing agent was added and kneaded for 4 minutes. Next, the kneaded material was mixed with a 6-inch roll, the vulcanizing agent was mixed, the blend was produced, and the Mooney viscosity was measured. Subsequently, the compound was put in a predetermined mold, press-vulcanized at 150 ° C. for 30 minutes to prepare a vulcanized product, and the physical properties thereof were measured. These results are shown in Table 3.

Example Comparative Example Product Name One 2 3 One 2 3 4 5 Prototype 1 Prototype 2 Prototype 3 BR150L BR700 Prototype 4 BR150B BR230

won
Ryo

The
radish Mooney Viscosity (ML) 40 44 47 40 38 60 40 38 n value 2.5 2.5 2.6 2.1 2.3 2.2 4.2 3.1 Sheath-1,4 content (%) 98 98 98 98 98 98 97 98 Mw (10 ⁴ ) 57 60 64 51 51 63 50 63 Mn (10 ⁴ ) 17 17 18 22 19 22 16 14 Mw / Mn 3.4 3.5 3.6 2.3 2.7 2.9 3.2 4.5 5% Toluene Solution Viscosity
(Tcp) 103 123 139 97 87 200 48 117 Tcp / ML 2.6 2.8 3.0 2.4 2.3 3.3 1.2 3.1 ship
synthesis
water Kneading processability 57 68 72 100 78 112 93 81 Formulation ML 94 96 98 100 92 110 94 92
end
sulfur
water Hardness 99 100 100 100 99 100 98 98 300% tensile stress 97 98 99 100 97 102 96 96 The tensile strength 99 101 100 100 99 102 98 97 Resilience 99 100 100 100 98 103 96 95 Carbon wear 104 104 106 100 98 105 88 90 Compounding prescription
BR / NR 50/50
Carbon black 50 product made by Tokai carbon company, sheath 9H (SEAST 9H)
Aroma Oil 3 Esso Sekiyusa Products 110
Zinc Oxide 3
Stearic acid 2
Antioxidant 2 Antigen 6C (N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine)
Vulcanization accelerator 1 Nocceler MSA (N-oxydiethylene-2-benzothiazoylsulfenamide)
Sulfur 1.5
150 ℃ × 30min Press Vulcanization

Claims (6)

High cis polybutadienes synthesized using cobalt-based catalysts include: (i) Mooney viscocity (ML): 40 to 49; (ii) Molecular weight distribution [weight average molecular weight (Mw) / number average molecular weight (Mn)]: more than 3.0 to 3.9 or less, and (iii) rate dependency index (n value) of Mooney viscosity: 2.3 to 3.0 (n value is as follows 5 to 90 parts by weight of a high cis polybutadiene (a) having a content of cis structure in the microstructure analysis of 95% or more, and other than the above (a). It is made by mix | blending 1-100 weight part of rubber reinforcing agents (c) with respect to 100 weight part of rubber components (a) + (b) which consists of 90-5 weight part of diene rubbers (b), The rubber composition for a tire, wherein the ratio (Tcp / ML) of the 5 wt% toluene solution viscosity (Tcp) and the Mooney viscosity (ML) of the high cis polybutadiene of (a) is greater than 2.5 to 3.5 or less. [Equation 1] log (ML) = log (K) + n ^-1 × log (RS) (Where RS is the revolutions per minute of the rotor and K is an arbitrary number). delete The rubber composition for a tire according to claim 1, wherein Mw of the high sheath polybutadiene of (a) is 500,000 to 700,000, and Mn is 120,000 to 250,000. The rubber composition for tires according to claim 1 or 3, wherein the rubber reinforcing agent of (c) is at least one of carbon black and silica. The rubber composition for tires according to claim 1 or 3, wherein the diene rubber of (b) is at least one of natural rubber and isoprene rubber. A tire comprising the rubber composition for tires according to claim 1 or 3 as a rubber base material.